Auxiliary carbon-contact circuit-breaker.



c., c. BADEAU. ALILRY CARBON CONTACT GIRGUIT BRBAKBB APPLioMII Hum JULY 27, 1909.

Patented May 14, 1912.

NITED. STATESv PATENT oFFicE,

CHARLES C. IBADEAU, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO SEARS lB. COITDI-T,.

JR., OF BOSTON, MASSACHUSETTS.

AUXILIARY CARBON-CONTACT CIRCUIT-BREAKER.

Specification of Letters Patent.

Patented May 14, 1 912.

Application'iled July 27, 1909. Serial No. 509,919.

a citizen of the United States, and resident of Boston, in the county of Suffolk and State of Massachusetts, have invented an Ii'nprovement in Auxiliary .Carbon-Contact Circuit-Breakers, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

In the usual circuit breaker the auxiliary or secondary contacts make maximum contact when closed, said contact decreasing or in other-words the resistance increasing as the circuit breaker opens.

Itis the object of my present invention to provide a circuit breaker having a secondary contact which provides a minimum resist ance to prevent arcing at said secondary as the circuit breaker is opening, having a position of maximum contact and hence niinimum resistance as the main contacts reach open position. Preferably I provide carbon secondary contacts, and these are preferably in the form of disks set edgewise so as to come flat against each other and be capable of being turned so as to bring a fresh separating or breaking pointinto operation when desired, or in other words the point of rupture is renewable simplyby turning the disks. Preferably also these disks are provided with a sharp peripheral edge, which reduces to a minimum the tendency to arc lupon separation. Preferably these fiat carbon contacts are set vertically edgewise parallel to the plane of their movement, and also preferably they are mounted in pairs and mountedfor mutual yielding when engaging each other.

My invention, which is especially designed lfor use with mains carrying currents of very high' volume and tension, and vusually for a considerable distance, from large generating plantsis to be distinguished from relatively small hand operated switches for controlling currents of much lower voltage and current. In the present circuit breaker, which is of considerable size and is to be openedV after being released by an automatic tripper, it is of the utmost importance that the secondary or final opening contacts be arranged for facile operation and so as to be not subject to clogging or obstruction by fouling of the engaging surfaces. I therefore consider the provision of the slidable ycarbon plates in the combination set forth an especially valuable feature as distinguished from certain constructions heretofore used in switches involving a carbon block arranged for slidable engagement with a metallic plate, such a construction being liable, if used in a high tension automatic circuitbreaker, to stick, by reason of fouling of the metallic surface.

The constructional details of my invention will be pointed out further and the invention set forth more at length in the 'following description, taken in connection with the accompanying drawings, and the invention will be further defined in the claims.

In the drawings, Figure 1 shows inside elevation a circuit breaker embodying my is open, most of the parts of the circuit v breaker being omitted so as to illustrate more clearly the carbon contact feature; Fig. 3 is a View substantially similar to Fig. 2 showing the parts in the closed position of the circuit breaker; and Fig. 4 is a top plan view of the contact portion of the circuit breaker.

My invention is applicable to a wide va riet-y of circuit breakers, the type herein shown comprising stationary contact blocks l, 2, a laminated bridge contact 3 coperating therewith, and an auxiliary metal shunt,Y contact 4, these together constituting the primary contacts carried by a support f5 `se cured at 6 in a switch lever 7 pivoted at 8 on xed supports and operated by a. handle lever-'9 pivoted at 10 to a tripping coil case 11, said l-ever having shoulders 12 to engage toggle links 13, 14 pivoted to each other at their meeting ends and at their opposite ends pivoted at 10 to said case and at 15 to said switch lever 7.

Extending forward from the switch lever 7 are 'arms 16, 1'7 provided at their outer ends with carbon contacts 1S, 19 in position to coperate with similar carbon contacts 20, 21, herein shown as supported by spring conductors 22, 23 secured at their lowerends to a stationary auxiliary contact block 24. The four carbon contacts 18-21 are shown as identical in shape and size, each'liaving a sharp peripheral edge 25 and adjacent beveled surfaces 26 and preferably 27, and. centrally pivoted so as to be capable of `be- 'ing rotatedwwhenit is Adesired to bring fresh l surfaces into operative position. These con- Y t\acts are lpreferably arranged so that when closed the movable contacts 18, 19pass below the relatively stationary contacts 20, 21 or' nearer to the switch bar 28'tlian said rel-y In use, when the circuit breaker, is open as' shown in dotted lines, Figl, the handle is moved from dotted line 'position .to closing 'position for closing the 'circuit breaker, which then assumes .the posit-ion shown in -ull lines, Fig. 1, the carboncontacts passingfrom their open position, Fig. 2, to their closed position, Figs. 3 and. 4. As the mov-` able contacts 'moveforwardly, their inner 'beveled surfaces .wedge against the,` outer beveled' suraces'of the vstationary contacts zo vand sprin the lattertoward each 'other so as e adjacent sides of the respect-ive contactsA into parallelism, further closing to brlng main contacts 1, 2m usual-v manner, followed v1- 30 by the auXilaryfmetal shunt` contacta, and

' finally the secondarycarbon contacts sepa rate, but instead 'of separating'in'usual mannem b'y .having -a maximum-contact closed position /which is Y gradually vlessened as the contactsgmove therefrom lto fully open' positionfthey first slide from the partially overlapped; position shown in Fig. 1` to coinci-` dent overlapping, position, so that, at' subl stantially itl/1.6 IIIQI'nfent"wl1en""'tl 1; primary '40 contacts have reachedcircuit breaking position', said secondary contacts have reached maximum-contact p'osition,"the yinner sides or -lat surfacesof the movable disks 18, 19l

bearing/,in direct co-extensive engagement 'With-'the outer' sides orv Hat surfaces of the stationarydisks- 20,' 21..' The spring supports 22', 23^and in securing" this maximum -contact-f minimum resistance; This.

' givesnot'- only perfect contact, butfsa-id minimum. resistance at the' time" when the moet;#perfect. freey path4 for"'current. is' de#- sirable, when the i main contacts "are .just separated., After the -main contacts have instr-separated; the further 'opening'move- Biment ofthe switch, or outward swing of vthe's vvvitchlever 7 y16, 17 serves gradually -fto'separa'te the movable' carbon disks 18, 19 @from 'the' yielding .stationary disks 2O, 21', vand as they arrive'l at the 'point o f separatortion, their' beveled surfaces'slide'in contact with each other and'finally the separating movement takes place at the sharp edges 25 -andat mutually tangential point-s thereof,V

L thereby reducing vto a minimum the tendency to'arc; By turning the disks on their pivots,

atively stationary contacts, as clearly shown new arcing edge-surfaces may be broughtyinto operative position as desired. Preferably also the disks are made reversible as shown.

Having. described my invention, what I claim as new and desire to secure byLetters Patent is: a

1. In an'electric circuitI breaker, primary and'secondary contacts 'having xed and movable elements, supporting means for the fixed elements, and carrying means for the movable elements, said secondary contacts having the fixed and movable elements thereof. of like. dimension `in the direction lofv relative movement and being mounted for flatvvise sliding frictional engagement,

and the contactsy being mountedon said supporting and carrying means so that as the. primary'- contacts separate the secondary contacts have substantially complete engagement of lftheir opposing latwise extending surfaces with undiminished frictional pressure, and the members comprising the secondarygcontacts being arranged s o that fur? ther movement of said carrying -means gradually diminishes the secondary 'contactf ing' surfaces to final separation.

2.1I-n an electric circuit breaker, primary and secondary contactshaving fixed and movable members, supportingmeansfor the fixed contacts and carrying means.. for the movable contacts, said secondary contacts being composed of flat plates of like dimension in the direction Yof relative movement mounted for flat-wise sliding frictiona'l engagement and being held from their outer sides only so as to leave the opposing sides free Vfor full contacting engagement, said secondarycontacts being mounted and arranged relative to the primary contacts so as to have substantially full surface en\` gagement With lundiminished pressure as the'primary contacts separate.

3. In an electric circuit breaker, primary and secondary contacts having' fixed and movable members, supporti-ng means for the fixed members and carrying means for the 'movable members, one ofy the members of` the primary contacts being a yielding one and relatively mounted 4for increasing contasting pressure [as the circuit f breaker is moved to fully closed position, and said sec- 4ondary contact-s being composed of ilatwise frictionallyengagi-ng plates of like dimension in the direction of relative movement arranged to occupy av position past maximum sep aration.

4. In an electric circuitbreaker, primary and secondary contacts having fixed and movable members, supporting means ".for the fixed members and carrying means 'for the movable members, said secondary contacts being composed .of flat disks of like dimension in the direction of relative movement held at their outer sides and arranged relative to the primary contacts so as to occupy positions past maximum co-ntact with the circuit breaker fully closed, and to have t-heir opposing faces 1n substantially full engagement with undiminished Apressure as said carrying member is moved to separate the primary contacts.

5. In an electric circuit breaker, secondary contacts mounted for relative movement to make and break a circuit, ne thereof being composed of a. carbon disk arranged to engage the other contact on its lateral surface with a tlatwise sliding engagement.,

said disk being mounted'for rotatable adjustment to present fresh peripheral arcing surfaces. .A

6. vIn an electric circuit breaker, second- Vary contacts composed of carbon disks mounted for relative movement to make and break a circuit and for tlatwlse sliding env gagement, said disks having axial mount'- ings and being adjustable about their axes to present fresh peripheral arcing surfaces.

7 In an electric .circuit breaker, separable /main contacts, final contactscomposedof c0- operating carbn disksl mounted edgewise in or parallel to the plan'e of their opening and closing movementarranged to slide in mutual tlatwise contact Wit-h each other, and having sharp' peripheral edges cooperating with 'each 'other in t-he final ruptureof the circuit with a minimum tendency to arc, and switch operating mechanism, said carbon disks havinga position of maximum contact following the separating movement of said main contacts.l 8. In an electric circuit breaker, secondary contactscomposed of carbon disks having ari -axial mounting fat one side thereof and arranged for fiatwise .sliding engageaxes to presentfres arcing surfaces.

In vtestimony whereof, I have signed my name to this specification, in the presence of l twosu'bscribing witnesses'.

' CHARLES C. BADEAU.

Witnesses:

` M. J. SPALDING, 'EnwAlzn` MAXWELL.

Copies of this patent may be obtained lor Ave cents each, by addressing the "Commissioner of Patents.

Washingtonl DL G.

ment, the disks bein adjustable a out their 

